Cooling controller for internal-combustion engine

ABSTRACT

The present invention relates to a cooling controller for cooling an internal-combustion engine such as an internal-combustion engine for an automobile, comprising a temperature detector for detecting the temperature of the cooling medium placed in a first or second circulation channel, and a flow control for controlling the flow of the cooling medium placed in the first or second circulation channel. 
     The first circulation channel passes through the engine and the radiator as in a conventional cooling system. The second circulation channel, which is used in case of a detected failure of the radiator or thermostat valve, includes the heat exchanger of the automobile&#39;s air-conditioning system. When the failure is detected an air conditioner controller maximizes the amount of heat radiated from the air conditioning exchanger to prevent overheating.

FIELD OF THE INVENTION

The present invention relates to a cooling controller for cooling aninternal-combustion engine such as an internal-combustion engine for anautomobile, and particularly to a cooling controller for aninternal-combustion engine that can prevent an internal-combustionengine from overheating in the case where the thermostat or other partsmay fail.

BACKGROUND OF THE INVENTION

In an internal-combustion engine (hereinafter abbreviated as “engine”)for use in an automobile, a water-cooled type cooling device using aheat exchanger (hereinafter referred to as “radiator”) for cooling theengine has been utilized. In such a cooling device, a thermostat isutilized as a cooling control means to control the temperature of thecooling water. If the temperature of the cooling water is lower than adesignated temperature, the thermostat is closed so the cooling watercirculates within a bypass route, not through the radiator. If thecooling water becomes higher than a designated temperature, thethermostat is opened and the cooling water circulates within theradiator.

The conventional cooling controller for an internal-combustion engine isshown in FIG. 7. In the cooling controller 100 for aninternal-combustion engine in this figure, a fluid passage shown by thearrow is formed within an engine E composed of a cylinder head 101 a anda cylinder block 101 b. Further, a cooling water channel 102 forcirculating the cooling water is placed between the engine E andradiator R.

The cooling water channel 102 is composed of a cooling water channel 102a connecting an outlet for the cooling water provided at an upperportion of the engine E with an inlet of the radiator R, a cooling waterchannel 102 b provided from an outlet of the radiator R to an inlet forthe cooling water provided at a lower portion of the engine E, and abypass channel 103 which connects the cooling water channel 102 a at theoutlet side to the cooling water channel 102 b at the inlet side. Athermostat 104 is placed on a branch portion between the cooling waterchannel 102 a at the outlet side and the bypass channel 103. Thethermostat 104 embeds a heat responding element, which expands orshrinks due to changes in the heat, like a wax does. When thetemperature of the cooling water is high, the valve is opened by theexpansion of the heat responding element to allow the cooling waterflowing from the engine E to enter into the radiator R via the coolingwater channel 102 a at the side of the outlet, and the cooling waterhaving a low temperature due to the heat radiation by the radiator Rpasses through the bypass channel 103 to flow into the cooling channelwithin the engine E from the inlet of the engine E.

When the temperature of the cooling water is low, the valve of thethermostat 104 is closed due to the shrinkage of the heat respondingelement, and the cooling water flowing from the outlet of engine Epasses through the bypass channel 103 to enter from the inlet of theengine E into the cooling channel within the engine E.

A water pump WP is placed at the inlet of the engine E, and by therotation of a crankshaft (not shown) of the engine E, the rotation shaftof the pump is rotated, forcing the cooling water to be circulated. Inaddition, the radiator R is provided with a cooling fan 105 for forcibleintake of the cooling air, and is composed of a cooling fan 105 and afan motor 106 for rotating the cooling fan 105.

The conventional cooling device described above has the followingproblems: when the fan motor 106 of the cooling fan 105 in the radiatorR has a problem, or any problem occurs in the thermostat 104 such as thevalve being left closed so the cooling water does not circulate into theradiator R, the cooling water is not cooled. Consequently, the engine Eattains a state of overheating.

A cooling controller for an internal-combustion engine according to thepresent invention has been made in light of the above situation, andprovides a system which can prevent problems such as overheating, evenif the radiator or the thermostat has failed and which can exhibitfail-safe functions.

SUMMARY OF THE INVENTION

A cooling controller for a internal-combustion engine according to thepresent invention which solves the problems described above, includes:

a first heat exchanger configured by forming a circulation channel for acooling medium between an internal-combustion engine and a heatexchanger to radiate out heat generated in the internal-combustionengine through circulation of the cooling medium, and a second heatexchanger which radiates out heat by forming a second circulationchannel for air conditioning an automobile cabin, the cooling controllerfurther comprising:

a temperature detecting means to detect the temperature of said coolingmedium, wherein the temperature detecting means is placed in at leastone of said first or second circulation channels,

a flow amount control means to control the flow amount of said coolingmedium,

a driving condition detecting means for said internal-combustion engine,

an internal-combustion engine control means to control saidinternal-combustion engine based on the output signal from said drivingcondition detecting means,

an air conditioner for air conditioning the automobile cabin utilizingthe heat radiation of said second heat exchanging system,

an air conditioner control means to control said air conditioner, and

said air conditioner control means outputting an operating signal whichmaximizes an amount of heat radiated from said second heat exchanger forair conditioning when an abnormality of the cooling function of saidinternal-combustion engine is detected by said input signal from saidinternal-combustion engine control means.

A cooling controller having such a configuration can allow the coolingmedium to cool down through the second heat exchanger, even if saidfirst heat exchanger or said flow amount control means is defective anddoes not allow the cooling medium to cool down, making it possible totake precautions against serious problems such as overheating.

Furthermore, said flow amount control means is preferably characterizedby opening or closing the thermostat valve through an input signal fromsaid internal-combustion engine control means.

The flow amount control means can carefully control the angle of thevalve and, thus, the flow amount in said first circulation channel canbe controlled with high reliability.

The present invention also relates to a cooling controller for aninternal-combustion engine comprising:

a first heat exchanger configured by forming a circulation channel for acooling medium between an internal-combustion engine and a heatexchanger to radiate out heat generated in the internal-combustionengine through circulation of the cooling medium, and a second heatexchanger which radiates out heat by forming a second circulationchannel for air-conditioning an automobile cabin, which coolingcontroller further comprises:

a temperature detecting means to detect the temperature of said coolingmedium, wherein the temperature detecting means is placed in at leastone of said first or second circulation channels,

a flow amount control means to control the flow of said cooling medium,

an air conditioner for air conditioning the automobile cabin having saidsecond heat exchanger and carrying out air conditioning utilizing thecooling medium of said internal-combustion engine,

an air conditioner control means to control said air conditioner, and

said air conditioner control means outputting an operating signal whichmaximizes an amount of heat radiated out from said second heat exchangerwhen the input signal from said temperature detecting means is higherthan a designated temperature.

The flow amount control means is preferably a thermostat which opens orcloses a valve by means of a thermal expansion means embedded in acasing.

A cooling controller for an internal-combustion engine having such aconfiguration has a relatively simple configuration, and canautomatically open or close the circulation channel of said coolingmedium.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a drawing showing a cooling controller for aninternal-combustion engine according to a first embodiment of thepresent invention;

FIG. 2 is a cross-sectional view showing a thermostatic valve for use inthe cooling controller of FIG. 1;

FIG. 3 is a drawing showing an air conditioner for use in the coolingcontroller of FIG. 1;

FIG. 4 is a drawing showing a cooling controller for aninternal-combustion engine according to a second embodiment of thepresent invention;

FIG. 5 is a cross-sectional view showing a thermostat for use in thecooling controller of FIG. 4;

FIG. 6 is a drawing showing functions of an air conditioner controlmeans for use in the cooling controller of FIG. 4; and

FIG. 7 is a drawing showing a cooling controller for aninternal-combustion engine according to the prior art.

Descriptions of parts which are the same as those of the conventionaldevice are omitted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A cooling controller for an internal-combustion engine according to afirst embodiment of the present invention will now be described byreferring to FIGS. 1 to 3.

In a cooling controller A for an internal-combustion engine shown inFIG. 1, a first circulation channel 1 for cooling fluid W, which is acooling medium, is formed between a fluid channel formed in an engine E,which is an internal-combustion engine, and a fluid channel formed in aradiator R, which is a heat exchanger. By circulating the cooling fluidW in the first circulation channel, heat generated in the engine E isradiated out through the radiator R. Further, a second circulationchannel 2, which is branched off the first circulation channel 1, isformed, and a heater core 21, which is a second heat exchanger and whichis used for air conditioning of an automobile cabin, is provided in thecirculation channel 2. It will be understood that the type of airconditioning of an automobile cabin provided by the second heatexchanger is heating. A bypass channel BC is also provided to allowcooling fluid W to flow in the first circulation channel 1 whilebypassing the radiator R.

A cooling fluid temperature sensor 3, which detects the temperature ofthe cooling fluid W, and which is a temperature detecting means, isplaced adjacent to the portion connecting the engine E to the first orsecond circulation channel. The cooling fluid temperature sensor 3detects the fluid temperature by the use, e.g., of a thermistor, etc.,and the temperature detected by the cooling fluid temperature sensor 3is converted into an electrical output signal and is output to theengine control unit ECU, which is the internal-combustion engine controlmeans.

At the channel portion between the channel branch 6 of the firstcirculation channel 1, the bypass channel BC, and the channel branch 6leading to the fluid pump WP, a thermostatic valve 10 is provided as avariable flow control means which controls the flow of the cooling fluidW. The thermostatic valve 10 controls the flow degree of the coolingfluid W by opening or closing an internal valve through an electriccontrol, as described more fully later on. The opening and closing ofthe valve is controlled by the engine control unit ECU.

At the connecting portion of the inlet 1 a of the first circulationchannel 1 to the engine E, a fluid pump WP for circulating the coolingfluid W is provided. The fluid pump WP is a gear pump driven by theengine E, and cools the engine E by passing the cooling fluid W througha fluid channel formed within the engine E, and circulates the coolingfluid W into the fluid channel of the radiator R via an output 1 b ofthe circulation channel 1. The cooling fluid W circulated into theradiator R is cooled down by cooling air, which is suctioned by theradiator fan 4, and the cooling fluid W having been cooled istransferred to the engine E via the inlet 1 a of the first circulationchannel 1. The radiator fan 4 is an electric fan which is driven by amotor 5, and the flow amount of air and ON-OFF switching are controlleddepending upon the temperature of the cooling fluid W. The control iscarried out by the engine control unit ECU based on the temperature ofthe cooling fluid W detected by the cooling fluid temperature sensor 3.

As shown in FIG. 2, the thermostatic valve 10 to be used in the coolingcontroller A for an internal-combustion engine is configured so that avalve body having a 3-way configured valve 11, having vanes 11 a and 11b, is placed between the inlet 1 a, the bypass channel BC, and thechannel branch 6 leading to the fluid pump WP, and the shaft 12 of the3-way configured valve 11 is driven by a drive motor 14 via adeceleration mechanism 13 to open or close the 3-way configured valve11. In the embodiment shown in FIG. 2, vane 11 a opens to allow flowfrom inlet 1 a to channel branch 6 as vane 11 b closes to cut off flowfrom bypass channel BC to channel branch 6, and vice versa. Between thedeceleration mechanism 13 and the drive motor 14, an electronic clutch15 is placed so as to break off the rotation of the drive motor 14.Between the valve body and the deceleration mechanism 13, a returnspring 16 is equipped to apply a resilient force against the 3-wayconfigured valve 11 in a direction so that the 3-way configured valve 11returns to a fail-safe normal position.

The thermostatic valve 10 configured as described above is controlled bythe engine control unit ECU, so that when the temperature of the coolingfluid W is less than a designated temperature, the valve is maintainedin a position that bypasses the radiator R, and when it is higher than adesignated temperature, the valve is positioned at an adequate angledepending upon the cooling fluid temperature to allow a variable flow ofcooling fluid W through the radiator R.

The engine control unit ECU, which controls the thermostatic valve 10and the radiator R as well as the driving state on the whole, and whichincludes a microcomputer, keeps the driving conditions of the engine Eunder control by inputting data on the rotation speed of the Engine E,the degree of opening of the throttle, and other parameters throughvarious driving condition sensors DCS, the cooling fluid temperaturesensor 3, as well as other sensors OS, and outputs a control signal toeach of the control devices to maintain the most ideal drivingconditions.

An air conditioner AC which controls a heater core 21, which is thesecond heat exchanger, based on an output signal from the engine controlunit ECU will now be described by referring to FIG. 3. In this figure,the air conditioner AC is composed of the body 20 of the device and acontrol part 30 for controlling air conditioning, which controls thebody 20 of the device.

In the body 20 of the device, the heater core 21 is placed in thecirculation channel 2, and heat exchange is carried out by passing thecooling fluid W through the heater core 21. For this reason, a blowerfan 22 is placed at the heater core 21, and by controlling the speed ofthe blower fan 22, the amount of heat radiated out can be controlled.

An air mix door 23 is also placed on the body 20 of the device for thepurpose of mixing the hot air transferred from the heater core 21 withthe cooling fluid W for controlling the temperature. The air mix door 23actuates to a given position according to the set temperature by meansof an air mix door actuator 23 a based on control by the control part 30for controlling the air conditioning. Further, an air blowing mode door24 switches the air, controlled to a designated temperature at the airmix door 23, into an air blowing mode such as DEF, VENT, or FOOT, and isactuated by means of an air blowing mode actuator 24 a through controlby control part 30 for controlling the air conditioning.

The body 20 of the device further possesses an evaporator 25 for formingcooling air for air conditioning. The evaporator 25 is driven by anoutdoor unit 25 a for the air conditioner through a control signal ofthe control part 30.

Also, an intake door 26 for switching intake of the air from inside oroutside of the automobile cabin is placed on the body 20 of the device.The intake door 26 has a configuration so as to be actuated by means ofan intake door actuator 26 a based on a control signal from control part30.

The control part 30 has a microcomputer etc., and drives the body 20 ofthe device according to an input signal input from an operation panel 31placed on a dashboard, etc., in the automobile cabin. On the operationpanel 31 are placed an air conditioning switch 31 a, which turns the airconditioner AC ON or OFF, a mode switch 31 b which switches theair-blowing mode to DEF, VENT, or FOOT, an intake switch 31 c whichswitches intake of the air from inside or outside of the automobilecabin, a temperature control switch 31 d, which controls the settemperature, and a display unit 31 e for displaying the contents set bythese switches. Further, the control part 30 controls the blower fan 22,the air mix door 23, the air-blowing mode door 24, the intake door 26,etc., to desired operating points by comparing the conditions set at theoperation panel 31 with the present temperature input from varioustemperature sensors 32, such as the external atmospheric temperaturesensor 32 a, the internal atmospheric temperature sensor 32 b, and thesolar sensor 32 c.

Further, the control part 30 is configured so as to input the outputsignal from the engine control unit ECU. The output signal from theengine control unit ECU is configured so that it is output when anydefect of the radiator fan 4 or the thermostatic valve 10 shown in FIG.1 occurs, making the cooling fluid temperature at the cooling fluidtemperature sensor 3 abnormal. In control part 30, when an abnormalsignal is input from the engine control unit ECU, the blower fan 22rotates at the maximum speed to maximize the heat radiation from theheater core 21. The control part 30 is configured so that when anabnormal signal is input from the engine control unit ECU, theoccurrence of abnormality appears on the display unit 31 e of thedisplay panel 31.

The cooling controller A configured as described above makes it possibleto cool the cooling fluid W by radiating out heat through the heatercore 21, even if the radiator fan 4 or the thermostatic valve 10 has aproblem. Furthermore, a driver can deal with the abnormality in anadequate manner based on the display of the occurrence of theabnormality on the display unit 31 e, thereby preventing problems aheadof time.

A cooling controller for an internal-combustion engine according to asecond embodiment of the present invention will now be described byreferring to FIGS. 4 to 6. Parts which are the same as those of thecooling controller A are represented by the same symbols.

In a cooling controller B for an internal-combustion engine shown inFIG. 4, a first circulation channel 1 for cooling fluid W, which is acooling medium, is formed between a fluid channel formed in an engine E,which is an internal-combustion engine, and a fluid channel formed in aradiator R, which is a heat exchanger. By circulating the cooling fluidW in the first circulation channel, heat generated in the engine E isradiated through the radiator R. Further, a second circulation channel 2which is branched off the first circulation channel 1, is formed, and aheater core 51, which is a second heat exchanger and which is used forair conditioning an automobile cabin, is provided in the circulationchannel 2 for air conditioning. A bypass channel BC is also provided toallow cooling fluid W to flow in the first circulation channel 1 whilebypassing the radiator R.

In cooling controller B a cooling fluid temperature sensor 3, whichdetects the temperature of the cooling fluid W, and which is atemperature detecting means is placed adjacent to the portion connectingthe engine E to the first or second circulation channel. The coolingfluid temperature sensor 3 detects the cooling fluid temperature by theuse of an, e.g., thermistor, etc., and the temperature detected by thecooling fluid temperature sensor 3 is converted into an electricaloutput signal and is output to the control part 60.

At the channel portion between the inlet 1 a of the first circulationchannel 1, the bypass channel BC and the channel branch 6 leading to thefluid pump WP, a thermostat 40 is provided as a variable flow controlmeans which controls the flow of the cooling fluid W. The thermostat 40includes a heat responding element 44 and opens or closes valves 42 and48 depending on the cooling fluid temperature to control the flow amountof the cooling fluid W, as described later on.

At the connecting portion of the inlet 1 a of the first circulationchannel 1 to the engine E, a fluid pump WP for circulating cooling fluidW is provided. The fluid pump WP is a gear pump driven by the engine E,and cools the engine E by passing the cooling fluid W through a fluidchannel formed within the engine E, and circulates the cooling fluid Winto the fluid channel of the radiator R via an output 1 b of thecirculation channel 1. The cooling fluid W circulated into the radiatorR is cooled down by cooling air, which is suctioned by the radiator fan4, and the cooling fluid W having been cooled is transferred to theengine E via the inlet 1 a of the first circulation channel 1. Theradiator fan 4 is an electric fan which is driven by a motor 5, and theair amount is automatically controlled depending upon the temperature ofthe cooling fluid W.

As shown in FIG. 5, the thermostat 40 which is used in the coolingcontroller B is placed at the channel portion between the firstcirculation channel 1, the bypass channel BC, and the channel branch 6leading to the fluid pump WP. The movable valve 42 is placed within aframe 41 fixed on the wall of the circulation channel, and the valve 42opens or closes the inlet 1 a from the radiator R. The movable valve 48is attached to a casing 46 of a thermo element 43 which is stored withinthe frame 41, and the valve 48 opens or closes the inlet from the bypasschannel BC. When the heat responding element 44 embedded in the thermoelement 43 pushes the valves 42 and 48 by heat expansion, the coolingfluid W is gradually allowed to pass through the radiator R, and iseventually substantially prevented from flowing through the bypasschannel BC. Specifically, when the heat responding element 44 thermallyexpands, a piston rod 45 is pushed up, but since the end portion of thepiston rod 45 is held by the frame 41, the casing 46 of the thermoelement 43 is conversely pushed down. For this reason, a push plate 47pushes the valve 42 down to make a gap between the valve 42 and theframe 41, and causes the valve 48 to seal off the inlet of the bypasschannel BC. The cooling fluid W is then routed through the radiator andsubstantially prevented from flowing through the bypass channel BC.

The thermostat 40 configured as described above is set so as to keep thevalve in a closed state with respect to the radiator R so cooling fluidW does not flow through the radiator R when the temperature of thecooling fluid W is less than a designated temperature, and to open thevalve with respect to the radiator R so cooling fluid W does flowthrough the radiator R when the temperature of the cooling fluid W ishigher than a designated temperature.

Next, an air conditioner AC will now be described by referring to FIG.6. In this figure, the air conditioner AC is composed of the body 50 ofthe device and a control part 60 for controlling the air conditioning,which controls the body 50 of the device.

In the body 50 of the device, the heater core 51 is placed in thecirculation channel 2, and heat exchange is carried out by passing thecooling fluid W through the heater core 51. For this reason, a blowerfan 52 is placed on the heater core 51, and by controlling the speed ofthe blower fan 52, the amount of heat radiated out can be controlled.

An air mix door 53 is also placed on the body 50 of the device for thepurpose of mixing the hot air transferred from the heater core 51 withthe cooling fluid W for controlling the temperature. The air mix door 53is actuated to a given position according to the set temperature bymeans of an air mix door actuator 53 a, based on control by the controlpart 60. Further, an air blowing mode door 54 switches the aircontrolled to a designated temperature at the air mix door 53 into anair blowing mode such as DEF, VENT, or FOOT, and is actuated by means ofan air blowing mode actuator 54 a through control by control part 60 forcontrolling the air conditioning.

The body 50 of the device further possesses an evaporator 55 for formingcooling air for air conditioning. The evaporator 55 is driven by anoutdoor unit 55 a through a control signal of the control part 60.

Also, an intake door 56 for switching the intake of air from inside oroutside of the automobile cabin is placed on the body 50 of the device.The intake door 56 has such a configuration so as to be actuated bymeans of an intake door actuator 56 a based on a control signal fromcontrol part 60.

The control part 60 for controlling the air conditioning has amicrocomputer etc., and drives the body 50 of the device according to aninput signal input from an operation panel 61 placed on a dashboard,etc. in the automobile cabin. On the operation panel 61 are placed anair conditioning switch 61 a, which turns the air conditioner AC ON orOFF, a mode switch 61 b which switches the air-blowing mode to DEF,VENT, or FOOT, an intake switch 61 c which switches intake of the airfrom inside or outside of the automobile cabin, a temperature controlswitch 61 d, which controls the set temperature, and a display unit 61 efor displaying the contents set by these switches. Further, the controlpart 60 controls the blower fan 52, the air mix door 53, the air-blowingmode door 54, the intake door 56, etc., to desired operating positionsby comparing the conditions set at the operation panel 61 with thepresent temperature input from various temperature sensors 62, such asthe external atmospheric temperature sensor 62 a, the internalatmospheric temperature sensor 62 b, and the solar sensor 62 c.

Further, the control part 60 is configured so as to input the outputsignal from the cooling fluid temperature sensor 3. At the time of anabnormally high output from sensor 3, the microcomputer within thecontrol part 60 causes the blower fan 52 to be rotated at the maximumspeed to maximize the heat radiating out from the heater core 51. Atthis time, the occurrence of abnormality appears on the display unit 61e of the display panel 61.

The cooling controller B for an internal-combustion engine configured asdescribed above makes it possible to cool the cooling fluid W byradiating out heat through the heater core 51, even if the radiator fan4 or the thermostat 40 has failed. Furthermore, a driver can deal withthe abnormality in an adequate manner based on the display of theoccurrence of the abnormality on the display unit 61 e of the operationdisplay panel 61, thereby preventing problems such as overheating aheadof time.

When an abnormally high temperature of the cooling fluid W is detectedby the cooling fluid temperature sensor 3, fail-safe can be moreeffectively carried out by the combination of maximum heat radiationmeasures such as by opening the intake door 56 for introducing externalatmospheric air, driving the blower fan 56 at the maximum, stopping theoutdoor unit 55 a of the air conditioner, and allowing the maximum heatto radiate out of the heater core 51.

Thus, in the invention, when a defect occurs in the radiator or thethermostat in an automobile, etc., so that the cooling fluid cannot becooled by the radiator, the cooling fluid can be cooled through a heatercore of the air conditioner and, thus, problems with overheating can beavoided.

What is claimed is:
 1. A cooling system for an internal-combustionengine comprising: a first heat exchanger; a first circulation channelfor circulating a cooling medium between said internal-combustion engineand said first heat exchanger to radiate heat generated in saidinternal-combustion engine through circulation of said cooling medium; asecond heat exchanger; a second circulation channel, wherein said secondheat exchanger is located in said second circulation channel, andwherein said cooling medium flows through said second circulationchannel; a temperature detector for detecting the temperature of saidcooling medium, wherein said temperature detector is placed in at leastone of said first or second circulation channels; a flow controller forcontrolling the flow of said cooling medium; an internal-combustionengine control unit for controlling said internal-combustion engine; anair conditioner for air conditioning said automobile cabin utilizing theheat radiation of said second heat exchanger; and an air conditionercontroller for controlling said air conditioner; wherein said airconditioner controller outputs an operating signal which maximizes anamount of heat radiated from said second heat exchanger when anabnormality of any driving condition of said internal-combustion enginerelating to engine overheat is detected via an abnormality signal fromsaid internal-combustion engine control unit.
 2. The cooling system foran internal-combustion engine as claimed in claim 1, wherein said flowcontroller opens or closes a valve based on a flow control signal fromsaid internal-combustion engine control unit to control the flow of saidcooling medium.
 3. The cooling system for an internal-combustion engineas claimed in claim 1, wherein said temperature detector is locatedsubstantially adjacent to said internal-combustion engine.
 4. Thecooling system for an internal-combustion engine as claimed in claim 1,wherein said first and second circulation channels share a coolingmedium passage inside said internal-combustion engine.
 5. The coolingsystem for an internal-combustion engine as claimed in claim 1, furthercomprising: a cooling medium pump which circulates said cooling mediumthrough said first and second circulation channels; wherein said firstcirculation channel includes a bypass channel for bypassing said firstheat exchanger; wherein said first heat exchanger has an input channelportion and an output channel portion; wherein said flow controller is athree-way configured flow control device, having anormally-open-when-cool port connected to said bypass channel, anormally-closed-when-cool port connected to one of said input and outputchannel portions of said first heat exchanger, and an always-open commonport connected to a channel portion leading to said cooling medium pump;wherein said flow controller is controlled to flow said cooling mediumthrough said bypass channel when said temperature of said cooling mediumis lower than a first designated temperature, and wherein said flowcontroller is controlled to flow said cooling medium through said firstheat exchanger when said temperature of said cooling medium is higherthan a second designated temperature.
 6. The cooling system for aninternal-combustion engine as claimed in claim 5, further comprising: afan for increasing heat dissipation from said first heat exchanger; anda fan controller for turning on said fan when said temperature of saidcooling medium is higher than a third designated temperature.
 7. Thecooling system for an internal-combustion engine as claimed in claim 1,further comprising: an air conditioning fan, wherein said airconditioner controller maximizes the flow of air by said airconditioning fan in order to maximize said amount of heat radiated fromsaid second heat exchanger.
 8. The cooling system for aninternal-combustion engine as claimed in claim 1, further comprising: awarning indicator, located in said automobile cabin, that displays awarning message when said abnormality of any driving condition of saidinternal-combustion engine relating to engine overheat is detected viasaid abnormality signal from said internal-combustion engine controlunit.